Use of a recuperator, while improving efficiency of a gas turbine engine, can also have a number of disadvantages. One such potential disadvantage is the reduction of power of a turbine engine that includes a recuperator. As may be appreciated, passing compressed air from the compressor and also the exhaust gas through the ducting associated with a recuperator, results in a pressure drop of the compressed air and exhaust gas thereby reducing the high-end performance (e.g., maximum power) of the engine. Such reduced power output is especially disadvantageous in aircraft and helicopter applications where maximum power is often desired and/or necessary during takeoff or hot and high altitude flying.
Another potential disadvantage is the increased weight and encumbrance of a turbine engine incorporating a recuperator. Such a disadvantage is also evident in aircraft applications where turbine engines are often utilized due to their high power to weight ratio. This limits the practical size of the recuperator that can be used and therefore reduces the efficiency gains that can be achieved. Practical ways of incorporating a recuperator in an aircraft engine, such as a PT6 model engine for example, are therefore sought while minimizing such disadvantages.